Coal Tar Pitch Derived sp2 Configuration‐Dominated Vacancy‐Rich Carbon with Expand Interlayer Spacing for Low‐Voltage, Durable, and Fast Potassium Storage

Abstract

AbstractThe low‐voltage charging capacity and rate performance are two crucial but mutually restricted properties of K‐ion batteries. Herein, a sulfonamide and amide linkages‐triggered N doping high‐temperature removal strategy is proposed to obtain porous carbon with rich carbon vacancies, high sp2 hybridized C content (65.3%), and large interlayer spacing using coal tar pitch as carbon precursor. Carbon vacancies and sp2 hybridized C are proved to be not only active sites for low‐voltage potassium storage but also conducive to the fast transfer of ions and electrons, endowing reversible and fast potassium storage at low voltage. Moreover, abundant carbon vacancies and large carbon interlayer spacing alleviate volume variation, improving the cycling stability for 8500 cycles (about 3700 h). This work sheds new light on the design of low‐voltage, durable, and fast potassium storage carbon anodes, and promotes the development of practical carbon anodes for high energy density K‐ion batteries in the future.